RF capacitive coupled etch reactor

ABSTRACT

In a capacitive coupled etch reactor, in which the smaller electrode is predominantly etched, the surface of the larger electrode is increased by a body e.g. a plate, which is on the same electric potential as the larger electrode and which is immersed in the plasma space. A pattern of openings in which plasma may burn is provided in the body so as to control the distribution of the etching effect on a substrate placed on the smaller electrode.

The present invention is directed to a two-electrode capacitive coupledRF etch reactor or apparatus and obeys substantially the law of Koenigas e.g. addressed in U.S. Pat. No. 6,248,219. In such a reactor orapparatus, the plasma space is in operational contact solely with anelectrode arrangement which consists of a first electrode arrangementand of a second electrode arrangement facing the first electrodearrangement. The law of Koenig defines that the ratio of the drop oftime averaged electrical potential adjacent to the electrode surfacesbetween which an Rf plasma discharge is generated, is given by theinverse ratio of respective electrode surface areas raised to the fourthpower. The conditions for which the law of Koenig is valid are alsoaddressed in the patent as mentioned. Therefrom results the skilledartisan's knowledge, that the smaller electrode surface exposed to theRf plasma is predominantly sputtered off, in other words etched, thelarger being predominantly sputter coated.

It is an object of the present invention to provide an improved etchingreactor or apparatus of the addressed type.

This is achieved by a capacitive coupled RF vacuum etching apparatusconstructed for etch operating under predetermined conditions, includingpredetermined pressure conditions. Such apparatus comprises a vacuumrecipient—also addressed as enclosure—.

In the vacuum recipient, a plasma space is provided which is contactsolely with one electrode arrangement consisting of a first electrodearrangement and of a second electrode arrangement facing the firstelectrode arrangement. Other members which are not electricallyconductive or which are operated in an electrically floating manner maybe in contact with the plasma space but are not to be considered aselectrodes.

The fact, that the plasma is operated and influenced by only twoelectrodes is essential for a Koenig type reactor.

The first electrode arrangement defines a first electrode surfaceexposed to the plasma space.

The second electrode arrangement defines a second electrode surfaceexposed to the plasma space and comprises the surface of a workpiececarrier with a carrier surface.

The first electrode surface is larger than the second electrode surface.

The first electrode arrangement is electrically connected to andsupplied from an output arrangement of a Rf generator arrangement via amatch box arrangement.

The first electrode arrangement comprises a metal body with asurrounding surface freely exposed to and immersed in the plasma spacewhereby the surrounding surface is a part of the first electrodesurface.

When we address that the surrounding surface of the body is freelyexposed to the plasma space, it is clear that some minor and neglectableparts of that surface are not freely exposed but are necessarily used toestablish a mechanical mount for the body within the plasma space.

By means of such a body the effective surface of the first electrodearrangement is significantly enlarged.

In one embodiment of the apparatus according to the invention the metalbody comprises a pattern of through openings and/or through slitstailored so that, in operation, plasma burns in the through openings atthe predetermined conditions.

By such trough openings and/or through slits plasma distribution in theplasma space may be controlled and thus the distribution of etchingeffect on the workpiece or substrate.

In one embodiment of the apparatus according to the invention the firstelectrode surface comprises a first surface area extending along a firstplane, a second surface area of said body, extending along a secondplane, said first and second surface areas defining an interspacetailored so that, in operation, plasma burns in and along the interspaceat the predetermined conditions.

If such body is constructed and mounted to just form an interspace witha width just large enough to allow plasma to burn therein but notsignificantly larger, the effective surface of the first electrodebecomes significantly enlarged without significantly increasing theoverall volume of the plasma space and thus of the vacuum recipient.

In one embodiment of the apparatus according to the invention the secondelectrode surface comprises a surface area extending along a third planeand said first, second and third planes are parallel planes.

Thus, the reactor is, in one embodiment and principally, a parallelelectrode reactor.

In one embodiment, the addressed metal body is a plate.

In one embodiment the capacitive coupled RF vacuum etching apparatusaccording to the invention the Rf generator arrangement generates atleast one first plasmas supply signal at a very high frequency at theoutput arrangement and at least one second plasma supply signal at ahigh frequency lower than the very high frequency at the outputarrangement and the first electrode arrangement is electricallyconnected via a match box arrangement to the output arrangement and iselectrically supplied, in operation, by the first and by the secondplasma supply signals.

The second electrode arrangement is, at least during etching operation,electrically connected to a system ground tab.

Due to the dual—or even multiple—Rf-frequency supply of the plasma inthe plasma space, the plasma density and thus etching efficiency issignificantly increased.

Nevertheless, the overall construction of the reactor or apparatus issignificantly facilitated by the fact that only the first electrodearrangement is multiple Rf supplied and provided with a match boxarrangement, whereas the second electrode arrangement is kept onelectrical ground potential. As it is this second electrode arrangementwhich provides for the workpiece support, the construction of workpiecehandling equipment is thereby substantially simplified as well.

In one embodiment of the apparatus according to the invention the firstplasma supply signal and the second plasma supply signal are connected,via the match box arrangement, to the first electrode arrangement atlocally different contact points.

In one embodiment of the apparatus according to the invention the Rfgenerator arrangement is connected, via the match box arrangement, tothe first electrode arrangement at more than one locally differentcontact points.

Both embodiments just addressed may improve plasma distribution in theplasma space and, especially for etching large workpieces or substrates,may contribute to reducing the occurrence of standing waves.

In the embodiments of the apparatus according to the invention, inwhich, as was addressed, at least a first very high frequency and asecond high frequency supply signal are applied to the first electrodearrangement, in one embodiment there is valid:10 MHz≤f_(vhf)≤400 MHz,or10 MHz≤f_(vhf)≤300 MHzor20 MHz≤f_(vhf)≤300 MHzor20 MHz≤f_(vhf)≤100 MHzand:0.01 f_(vhf)≤f_(hf)≤0.5 f_(vhf)or0.05 f_(vhf)≤f_(hf)≤0.5 f_(vhf).

Thereby f_(hf) stands for the frequency of the high frequency supplysignal and f_(vhf) stands for the frequency of the very high frequencysupply signal.

In one embodiment of the apparatus according to the invention theworkpiece carrier is drivingly movable towards and from the firstelectrode arrangement.

In one embodiment of the apparatus according to the invention theworkpiece carrier is not movable towards and from the first electrodearrangement.

In one embodiment of the apparatus according to the invention theworkpiece carrier is not movable towards and from the first electrodearrangement and the first electrode arrangement comprises a drivinglymovable door for loading/unloading a workpiece.

In one embodiment of the apparatus according to the invention theenclosure is subdivided in a pumping compartment comprising a pumpingport and in an etching compartment comprising the first electrodearrangement. The compartments are separate by a shroud or rim which hasa pattern of through openings and/or through slits tailored so that, inoperation, plasma does not burn therein at the predetermined etchingconditions.

Such two-compartment structure allows to realize high pumping efficiencythrough a large pumping port although keeping the etching compartmentsmall, just adapted to the specific workpiece or substrate and theelectrode arrangements. The etching compartment volume may be fullyexploited for the electrode arrangements without considering pumpingport requirements.

In one embodiment of the apparatus according to the invention theenclosure is subdivided in a pumping compartment which comprises apumping port and in an etching compartment, which comprises the firstelectrode arrangement. The compartments are separate by a shroud or rim.The shroud or rim holds a frame which defines a workpiece access openingto the etching compartment. The frame is held by the shroud or rim bymeans of a multitude of spokes which mutually define through-gapsbetween the pumping compartment and the etching compartment. The gapsare tailored so that, in operation, plasma does not burn therein. In afurther embodiment, the frame is thereby held by the rim or shroud bymeans of the spokes in such a manner, that the frame may freely expandand retract under thermal loading.

In one embodiment of the apparatus according to the invention theenclosure is again subdivided in a pumping compartment comprising apumping port and an etching compartment comprising the first electrodearrangement. The compartments are separate by a shroud or rim having apattern of through openings or through slits tailored so, that, inoperation, plasma does not burn therein at the predetermined etchingconditions. The shroud or rim holds a frame which defines a workpieceaccess opening to the etching compartment. The workpiece carrier isdrivingly movable from a load-/unload position into a processingposition and vice versa. The frame acts as a downholding member for aworkpiece or substrate on the workpiece carrier in the processingposition.

The skilled artisan knows as to when a vacuum plasma will burn or willnot burn in a void e.g. in a hole, in a slit in an interspace, whenpredetermined processing conditions are applied.

In one embodiment of the apparatus according to the invention theenclosure is again subdivided in a pumping compartment comprising apumping port and in an etching compartment which comprises the firstelectrode arrangement. The compartments are separate by a shroud or rim.The shroud or rim holds a frame which defines a workpiece access openingto the etching compartment. The workpiece carrier is drivingly movablefrom a load-/unload position into a processing position and vice versa.The frame is constructed so as to act as a downholding member for aworkpiece or substrate on the workpiece carrier in the processingposition. The shroud or rim holds the frame by means of a multitude ofspokes mutually defining through-gaps between the pumping and theetching compartments. The through-gaps are tailored so, that, inoperation, plasma does not burn therein at the predetermined etchingconditions. The frame is held by the rim or shroud by means of thespokes so that it may freely expand and retract under thermal loading.

In one embodiment of the apparatus according to the invention the spokesare constructed as compressible and/or bendable members and thusresiliently allow free expansion and retraction of the frame.

In one embodiment of the apparatus according to the invention at least apart of the spokes define a direction of length extent each and aremounted to the frame so, that the respective direction of length extentintersects the tangent on said frame at the locus of respective spokefixation with an angle α for which there is valid:90°>α≥0°.

In one embodiment of the apparatus according to the invention theworkpiece carrier comprises a channel arrangement adapted to receive aliquid heating or cooling medium.

In one embodiment of the apparatus according to the invention theenclosure is subdivided in a pumping compartment comprising a pumpingport and an etching compartment comprising the first electrodearrangement. The compartments are separate by a shroud or rim which hasa pattern of through openings and/or through slits tailored so that, inoperation, plasma does not burn therein at the predetermined etchingconditions. The workpiece carrier is drivingly movable from aload-/unload position into a processing position and vice versa. Adownholding member is provided tailored to mechanically hold a workpieceor substrate down on the workpiece carrier and in the processingposition at and along the periphery of the workpiece- orsubstrate-surface which is exposed to the etching compartment. Theworkpiece carrier comprises a channel arrangement adapted to receive aliquid heating or cooling medium and a further channel arrangementadapted to receive a heat conduction gas. The further channelarrangement discharges by a bore- or slit-pattern at the carrier-surfaceof the workpiece carrier.

In one embodiment of the apparatus according to the invention thefurther channel arrangement and bores or slits discharging at thecarrier-surface are tailored so as to establish along the periphery ofan interspace between said carrier-surface and a substrate or workpiecea pressure of heat conducting gas which is at least equal to thepressure in the and along the more central parts of said interspace.

In one embodiment of the apparatus according to the invention theenclosure is subdivided in a pumping compartment comprising a pumpingport and in an etching compartment comprising the first electrodearrangement. The compartments are separate by a shroud or rim having apattern of through openings and/or through slits which are tailored sothat, in operation, plasma does not burn therein at said predeterminedetching conditions. The shroud or rim is either a part of the enclosureor comprises a part of the enclosure and a part of the first electrodearrangement.

In one embodiment of the apparatus according to the invention theenclosure is subdivided in a pumping compartment comprising a pumpingport and in an etching compartment comprising the first electrodearrangement. The compartments are separate by a shroud or rim which hasa pattern of through openings and/or through slits. As was addressedbevor in different contexts, these openings and/or through slits aretailored so that, in operation, plasma is not burn therein at thepredetermined etching conditions. The workpiece carrier is drivinglymovable from a load-/unload position into a processing position and viceversa. The shroud or rim is electrically connected to the workpiecesupport in its processing position by distinct, distributed andresilient contact members.

In one embodiment of the apparatus according to the invention the Rfgenerator arrangement generates, as was addressed above, at least onefirst plasmas supply signal at a very high frequency at an outputarrangement and—simultaneously—at least one second plasma supply signalat a high frequency lower than said very high frequency, at the outputarrangement. The first electrode arrangement is electrically connectedvia a match box arrangement to the output arrangement and iselectrically supplied, in operation, by the first and by the secondplasma supply signals. The second electrode arrangement is electricallyconnected to a system ground tab and the frequency of first plasmasupply signal is about 60 MHz, the frequency of the second plasma supplysignal about 13 Mhz.

Please note that in all embodiments in which a very high frequencysupply signal as well as a high frequency supply signal are applied tothe first electrode arrangement these at least two supply signals aresimultaneously applied at least during time intervals of the etchingoperation.

In one embodiment of the apparatus according to the invention thepredetermined pressure condition for the etching is between 0.1 and 0.5Pa, both limits included.

In one embodiment of the apparatus according to the invention a spacingbetween a first part of the surrounding surface of the metal body freelyexposed to and immersed in the plasma space and a second part of thefirst electrode surface, facing the first part, is 10 mm to 40 mm,preferably 20 mm.

In one embodiment of the apparatus according to the invention, a spacingbetween a predominant part of the first electrode surface facing theworkpiece carrier and a predominant part of the surface of the workpiececarrier is 40 mm to 80 mm, both limits included, is preferably 65 mm.

One embodiment of the apparatus according to the invention is shaped forrectangular or square substrates.

In one embodiment of the apparatus according to the invention the Rfgenerator arrangement is constructed to at least one of frequencymodulating and of power modulating at least one RF supply signal duringoperation.

In one embodiment of the apparatus according to the invention at leastone of the following features prevails:

-   -   The Rf generator arrangement is tailored to supply a very high        frequency supply signal and high frequency supply signal to the        first electrode arrangement, the frequency of the very high        frequency supply signal being an integer multiple of the        frequency of the high frequency supply signal;    -   The Rf generator arrangement is tailored to supply a very high        frequency supply signal and high frequency supply signal to the        first electrode arrangement and to phase lock the addressed        supply signals;    -   The Rf generator arrangement is tailored to supply a very high        frequency supply signal and high frequency supply signal to the        first electrode arrangement and for adjusting mutual phasing of        the addressed supply signals;    -   The Rf generator arrangement is tailored to supply a very high        frequency supply signal and high frequency supply signal to the        first electrode arrangement and to vary mutual phasing of the        addressed supply signals during operation.

The invention is further directed on a workpiece or substrate processingplant comprising at least one capacitive coupled Rf apparatus accordingto the invention or one or more than one of its embodiments. In oneembodiment, the plant is an inline plant, including a coil-to-coil foilprocessing plant. In an inline plant, workpieces are transported in arow from one treatment station to the next at a fixed rhythm. In afurther embodiment, the plant is of the type in which the treatmentstations are loaded and unloaded with at least one workpiece orsubstrate at a selectable rhythm, as by a handler, e.g. a centralhandler.

The invention is further directed to a method of etching workpieces orsubstrates or of manufacturing etched workpieces or substrates by makinguse of the capacitive coupled RF vacuum etching apparatus according tothe invention or according to one or more than one of its embodiments,or of the plant according to the invention.

In one variant of the method according to the invention etching isperformed in a reactive gas atmosphere, preferably containing oxygen oroxygen and fluorine. Thereby oxygen as well as fluorine may be providedby a gas containing oxygen, oxygen e.g. by N2O and, respectivelyfluorine, by a gas containing fluorine, as e.g. by CF4, SF6, NF3, C4F8etc.

One or more than one of the embodiments of the capacitive coupled RFvacuum apparatus may be combined, if not contradictory.

The invention will now be further described by examples and with thehelp of figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 most schematically and simplified an embodiment of the apparatusaccording to the present invention.

FIG. 2 again schematically and simplified, an embodiment of theapparatus according to the invention and according to a view on theembodiment of FIG. 1 , seen from A-A in FIG. 1 ;

FIG. 3 schematically and simplified the link of the spokes to the frameof the embodiment of FIG. 2 in a perspective view;

FIG. 4 : schematically and simplified, an Rf supply of superimposedsupply signals to the first electrode arrangement, according to anembodiment of the apparatus according to the invention;

FIG. 5 : schematically and simplified, an Rf supply of supply signals tothe first electrode arrangement, according to an embodiment of theapparatus according to the invention;

FIG. 6 : schematically and simplified, a part of the rim or shroud of anembodiment of the apparatus according to the invention;

FIG. 7 : schematically and simplified, an embodiment of the apparatusaccording to the present invention, in which the substrate—orworkpiece—carrier is not lifted towards or retracted from the firstelectrode arrangement;

FIG. 8 : most simplified and schematically, an embodiment of theapparatus according to the present invention;

FIG. 9 : schematically and simplified the feature of enlarging theeffective surface of the first electrode arrangement at an embodiment ofthe apparatus according to the present invention;

FIG. 10 : schematically and simplified one variant of connecting thesecond electrode arrangement of an embodiment the apparatus according tothe invention to ground potential;

FIG. 11 : schematically and simplified one variant of realizingcooperation of the workpiece or substrate support and of the shroud orrim at an embodiment of the apparatus according to the invention;

FIG. 12 : schematically and simplified the principle of the shroud orrim construction as applied to one embodiment of the apparatus accordingto the invention;

FIG. 13 : schematically and simplified an embodiment of the shroud orrim construction as applied to one embodiment of apparatus according tothe invention and according to the principle explained with the help ofFIG. 12

FIG. 14 : schematically and simplified, in a partial cross-sectionalrepresentation along line B-B of FIG. 13 , the interaction of theliftable and retractable workpiece carrier with the substrate orworkpiece, with the rim or shroud and frame arrangement as of FIG. 13 .

FIG. 15 : schematically and simplified a partial representation of theworkpiece carrier as provided in one embodiment of the apparatusaccording to the invention;

FIG. 16 : schematically and simplified an inline plant according to thepresent invention with one or more than one apparatus according to theinvention;

FIG. 17 : schematically and simplified a further embodiment of the plantaccording to the invention;

FIGS. 18 and 19 : schematically and simplified further embodiments ofthe plant according to the invention.

We address throughout the present description and claims a frequency fas a very high frequency f_(vhf) if there is valid:10 MHz≤f_(vhf)≤400 MHz,or10 MHz≤f_(vhf)≤300 MHzor20 MHz≤f_(vhf)≤300 MHzor20 MHz≤f_(vhf)≤100 MHz.

We address throughout the present description and claims a frequency fas a high frequency f_(hf) if there is valid:0.01 f_(vhf)≤f_(hf)≤0.5 f_(vhf)or0.05 f_(vhf)≤f_(hf)≤0.5 f_(vhf).

The apparatus 1 of the embodiment of FIG. 1 and according to theinvention, which will also be called reactor, comprises a vacuum chamberwithin a metal enclosure 3. Within the enclosure 3 a pumping compartment5 is separate from an etching compartment 7 by a separating shroud orrim 9 having a dense pattern of through—holes and/or through—slits 11.The lower compartment, the pumping compartment 5, comprises a largepumping port 13 to which a pump arrangement 15 is connectable.

A metal workpiece support, also called substrate support, 19 has a firstmetal part 19 a rigidly mounted and electrically connected to the metalenclosure 3 and a movable part 19 b drivingly movable up and down, asshown by the double arrow W, with respect to the part 19 a. The movablepart 19 b carries a metal workpiece- or substrate-carrier 19 c. Thedrive for the parts 19 b and 19 c is not shown in FIG. 1 .

The part 19 c is, especially in its edging, upper position, electricallylinked to ground e.g. via a metal bellow 21 to part 19 a.

As schematically shown, the metal enclosure 3 is electricallyconnectable to a system ground-G-connector as e.g. shown in FIG. 1 at23.

The enclosure 3 is further electrically connected to shroud or rim 9e.g. at 25 and is electrically connected to part 19 a e.g. at 27. Part19 b is electrically connected to substrate carrier 19 c e.g. at 28.

Within the etching compartment 7 there is provided a first electrodearrangement 29. The first electrode arrangement 29 which provides forthe larger electrode surface of the reactor 1, thus the electrodesurface being predominantly sputter coated, comprises a jar- orpot-shaped electrode body 31 with a plate shaped basis 33 and frame likeside walls 35. The jar- or pot-shaped electrode body 31 resides close toand separate from and along the enclosure 3. It may e.g. be mounted tothe enclosure 3 via an electrically isolating layer or by electricallyisolating members (not shown).

The first electrode arrangement 29 is electrically connected to a supplygenerator arrangement 37, as shown by line 38, via a matchboxarrangement 39. Thereby the basis 33 of the electrode body 31 is, e.g.substantially centrally, connected to—according to one embodiment of theinvention—at least two outputs 41 _(vhf) and 41 _(hf) of an outputarrangement of the matchbox arrangement 39. From the output 41 _(vhf) afirst plasma supply signal with a f_(vhf) frequency supplies the firstelectrode arrangement 29 and, from output 41 _(hf) a second plasmasupply signal with a frequency f_(hf), superimposed on the first plasmasupply signal, supplies the first electrode arrangement 29. The firstand second plasma supply signals are generated by the supply generatorarrangement 37, e.g. comprising a generator for the first plasma supplysignal and a second generator for the second plasma supply signal. Thegenerator arrangement 37 has an output 40 _(vhf) as well as an output 40_(hf) to the matchbox.

The first and second plasma supply signals are simultaneouslyapplied—superimposed—to the first electrode arrangement 29, at leastduring a time interval within etch processing timespan, thereby evenduring a predominant time interval within the etch processing timespan,or even during the entire etch processing timespan.

The match box arrangement 39 is constructed to prevent that, due tosuperposition of the plasma supply signals, the vhf plasma supply signalloads the hf generator output and vice versa. As schematically shown inFIG. 1 a band block filter 43 _(vhf) tuned on the f_(vhf) generated atthe output 40 _(vhf) blocks signals from the output 40 _(vhf) to loadthe output 40 _(hf). In analogy, a band block filter 43 _(hf) tuned onthe f_(hf) generated at the output 40 _(hf) blocks signals from theoutput 40 _(hf) to load the output 40 _(vhf). This is equivalent tosupplying the electrode arrangement 29, respectively, via band-passfilters.

The second electrode arrangement 45 comprises the workpiece carrier 19 cof the workpiece support 19 in its lifted-up position (b), which is theetching position for a plate shaped workpiece or substrate residing onthe workpiece carrier 19 c.

As addressed above, the workpiece carrier 19 c is on system groundpotential. This significantly simplifies overall construction of thereactor, e.g. with an eye on handling substrates to and from thereactor. As the substrate is therefore operated on ground potential, theelectrode arrangement 29 is operated on a floating DC potential e.g. inthat it is—normally in the matchbox arrangement 39—decoupled from DC asby capacitive coupling to the supply generator arrangement 37, asschematically shown by capacitor 34.

Generically spoken, and in this embodiment, the larger electrode issupplied by different Rf frequencies and the substrate carrier, thesmaller electrode, is operated on ground potential.

The shroud 9, operated on ground potential, is, electrically, part ofthe second electrode arrangement 45. The RF plasma PL is confinedbetween the inner surface 31 i of the electrode body 31, the uppersurface 9 i of the shroud 9 and the surface 19 ci of the workpiececarrier 19 c exposed to the etching compartment 7.

Between the outer surface 310 of the electrode body 31 and the enclosure3 no plasma is generated, due to the fact that the interspace betweenthe enclosure 3 and the outer surface 310 of the electrode body 31 isrespectively conceived e.g. so, that the spacing is smaller than darkspace distance at the predetermined operating etching conditions or e.g.due to the fact that the respective interspace is filled with adielectric material spacing layer.

The through—openings or through slits 11 in the shroud 9 are dimensionedso small, that no plasma may burn therein at the addressed conditions.Through slits are narrower than the addressed dark space distance. Thediameters of through holes as well are smaller than the addressed darkspace distance. Nevertheless, the density of through bores or throughslits is high enough to ensure a very low gas flow resistance from theetching compartment 7 to the pumping compartment 5, ensuring a highlyefficient pumping-off of etched off material. As the through-bores or-slits 11 in the shroud 9 are dimensioned so that no plasma may burntherein, the surface increase of the second electrode arrangement 45 bysuch bores and/or slits does not influence sputtering/etchingdistribution between the electrode arrangements 29 and 45.

The etching efficiency of a substrate 47 is significantly improved bysubstantially enlarging the electrode surface of the first electrodearrangement 29. This is realized by providing at least one metal body 50e.g. plate shaped, distant from the surface 31 i of the electrode body31. The e.g. plate shaped, metal body 50 has an overall surroundingsurface 50 i, which, with the exception of some small areas for mountingand electrically feeding the body 50, is freely exposed to the plasmaspace PL. Electrically RF-supplied e.g. by both plasma supply signals,as schematically shown at 52 and spaced from the surface 31 i by adistance d1 larger than the dark space distance at the prevailingconditions for the etching process for the substrate 47, the e.g. plateshaped body 50 becomes completely immersed in the Rf plasma. Its overallsurface 50 i is part of the electrode surface of the first electrodearrangement 29.

Thus according to the invention, a metal body is immersed in the plasmaspace and at the Rf electric potential of the larger electrodearrangement in a reactor substantially obeying the law of Koenig.

By means of a selected pattern of through openings and/or through slits54, dimensioned to allow plasma burning there through, the etch-ratedistribution along the workpiece or substrate 47 may be adjusted, e.g.for dealing with border effects which may affect this distribution alongthe periphery of the substrate 47. To do so it is proposed to provide anincreased density of through openings along and in vicinity of asubstantial extent-parts of the periphery of the plate shaped body 50and/or to provide extended slits along and in vicinity of the addressedperipheral parts.

Blurring or picturing the through holes or through slits 54 in the plateshaped body 50 on the etch-rate distribution on the substrate 47 may beminimized by appropriately selecting the distance d2 between the surfaceof the substrate 47 to be etched and the surface of the plate shapedbody 50 large enough. In a good embodiment of the reactor 1, theaddressed through slits 54 are realized comprising or even consisting ofelongated slits along the periphery of the plate shaped body 50,neighboring the side wall 35 of the electrode body 31.

So as to minimize Rf return impedance to system ground G, the shroud orrim 9 electrically contacts the workpiece carrier 19 c e.g. by resilientcontact members 56 e.g. distributed all along the circumference of theworkpiece—or substrate carrier 19 c. Thereby in the embodiment of FIG. 1Rf current is led in parallel along the enclosure 3 and along theworkpiece support 19 to the system ground G.

Gas, especially just an inert working gas as e.g. Ar, is fed by a gasfeed line 53 into the plasma space PL. The reactor 1 may also be usedfor reactive plasma etching e.g. in an oxygen or oxygen plus fluorinecontaining atmosphere. In this case also the respective reactive gas orgas mixture is fed through a respective gas feed line to the plasmaspace.

Due to the fact, that a powerful pump arrangement 15 may be connected tothe large pumping port 13 in the separate pumping compartment 5, whichmay be dimensioned completely independently from dimensioning of theetching compartment 7 with the respective surface extent conditions forthe first and second electrode arrangements 29,45, and due to the factthat the plasma space PL is in gas-flow (not plasma) connection througha dense pattern of through openings or through slits 11 in the shroud 9,a highly effective pumping removal of etched off material from theetching compartment 7 is achieved.

It is to be noted, that in the frame of the present invention, thesubstrate carrier 19 c needs not be movable up and down towards and fromthe electrode arrangement 29 but may be provided stationary e.g. in theup position shown in FIG. 1 at (b).

FIG. 2 shows, again schematically and simplified, an example of the viewthrough the embodiment of FIG. 1 , seen from A-A of FIG. 1 . Thesubstrates to be etched are assumed rectangular or square. Thus, theshroud 9 frames the rectangular or square shaped handling opening 55(FIG. 1 ) to which the substrate carrier 19 c is lifted into etchingposition (in FIG. 1 (b)) or lowered towards substrate loading position(in FIG. 1 (a)). The shroud or rim 9 is a metal plate comprising a densepattern of through slits between spokes 12. According to this example,in one half of the shroud plate 11 the slits 11 extend substantially inthe direction of the one diagonal of the rectangular or square shroud,in the other half of the shroud or rim 9 in the direction of the otherdiagonal. The respectively directed slits are addressed in FIG. 2 by 11a and 11 b. There where the spokes 12 defining the slits 11 abut in thehandling opening 55 there ends 12 e are free as shown in FIG. 3 , freelysupported in a ceramic material frame 57. The slits are machined in theplate shaped shroud 9.

Due to the fact that, in this example, the ends 12 e of the spokes 12are free to expand relatively to the frame 57 as addressed by the doublearrow V in FIG. 3 , the parts of shroud 9 and the frame 57, most exposedto thermal loading by the Rf etching process, may freely expand relativeto one another, avoiding warpage of the shroud plate 9 and/or stressing,warping and possibly slightly displacing the ceramic material frame 57.

The ratio of solid material surface to open space surface of the slits11 is about 1:1 and the width d3 of the slits is between 3 mm and 10 mm.

Good operating parameters as used today:

Ar operating pressure: 0.1 to 0.5 Pa

f_(vhf): 60 MHz

f_(hf): 13.56 MHz

Power vhf supply signal<power of hf supply signal.

d1: larger than dark space distance at the addressed operatingconditions: d1≥20 mm

d2: larger than dark space distance at the addressed operatingconditions: d2≥65 mm

As schematically shown in FIG. 4 the superimposed vhf and hf plasmasupply signals may be fed to the first electrode arrangement 29 atlocally different contact points, C1 to Cn at the jar shaped electrodebody 31 and/or at contact points E1 to En to metal body 50.

As schematically shown in FIG. 5 , the vhf plasma supply signal and thehf plasma supply signal may thereby be supplied separately to the firstelectrode arrangement 29, electrode body 31 and/or metal body 50, atrespectively one or more than one locally different points C11 to C1 nand/or E11 to E1 n for the vhf supply signal and C21 to C2 n and/or E21to E2 n for the hf supply signal. Only one C1 x and/or E1 x and/or onlyone C2 x and/or E2 x contacting points are possible as well.

The electrode body 31 and/or the metal body 50 may be subdivided inmutually electrically isolated segments, each supplied with at least oneof the first and second plasma supply signals.

The Rf generator arrangement may further generate as a vhf first plasmasupply signal a signal which may be frequency modulated during etchoperation with respect to f_(vhf) and/or which may be power modulated.Additionally, or alternatively the generator arrangement may generate asa hf second plasma supply signal a signal which may be frequencymodulated during etch operation with respect to f_(hf), or which may bepower modulated.

The selected f_(vhf) may further be an integer multiple of the f_(hf),phase locked or not phase locked and possibly with adjustable, possiblytime varying mutual phasing. More than one second plasma supply signalsat different f_(hf) may be applied in superimposed manner to the firstelectrode arrangement 29.

As schematically shown in FIG. 6 the first electrode surface 31 i mayfurther be increased by realizing an upper part of the shroud or rim 9by a respective part 319 of the electrode body 31 and by spieling thebottom surface of the part 319 by a shield part 3 ₉ of the enclosure 3,defining an interspace to the part 319 narrower than dark space distanceat the intended etching conditions. Both, part 319 and 3 ₉ have alignedthrough openings or through slits 11 ₃₁ and 11 ₃ respectively. Clearlythe first electrode surface may further be significantly enlarged byshaping the plate shaped body 50 similar to body 31 jar- or pot-likeand/or by providing more than one of the metal bodies 50 e.g. plateshaped and staggered by more than dark space distance.

In the embodiment of FIG. 1 the workpiece carrier 19 c is dynamicallyoperated i.e. movable up and down. In its low handling position, it isloaded with a workpiece or substrate to be etched and an etch treatedworkpiece or substrate is unloaded e.g. through a bidirectionalload-lock 60. The workpiece carrier 19 c is moved from handling position(a) up into etching position (b) for a substrate to be etch treated andfrom etching position (b) down into handling position (a) to unload theetch treated substrate.

In FIG. 7 , most schematically and simplified, an embodiment is shownwhere the workpiece or substrate carrier 19 c is stationary i.e. is notmovable towards and from the first electrode arrangement. The electrodebody 31 may comprises a door 31 d which may be opened and closed e.g. bya drive 62. In closed position, the door may be a part of the electrodebody 31 and still contributes to the inner surface 31 i. The workpieceor substrate is loaded on and unloaded from the workpiece or substratecarrier 19 c e.g. via bidirectional load-lock 60.

The workpiece or substrate carrier may also be handled with a respectivesubstrate or workpiece trough the loadlock 60 and is thus in any casenot liftable towards and retractable from the first electrodearrangement 31.

Alternatively, the substrate or workpiece, with or without the workpieceor substrate carrier, may be loaded and unloaded pathing below the firstelectrode arrangement with the jar- or pot-like body 31 withoutproviding a door as of door 31 d in the body 31.

In FIG. 8 there is shown, most simplified and schematically, ancapacitive coupled RF vacuum etching apparatus obeying the law ofKoenig. The Rf plasma space is confined between a first, largerelectrode arrangement 829 and a second, smaller electrode arrangement845. The first, larger electrode arrangement is operated with a Rf drivesignal with at least one frequency and with respect to the metalenclosure 803 on a reference potential, e.g. on ground potential. Thus,there exists, in operation, a Rf potential difference between the metalenclosure 803 and the larger electrode arrangement 829. The spacing d4between the outer surface 831 _(o) of the electrode arrangement 829 andthe inner surface of the enclosure 803 wall is decisive for the Rf powerloss from the electrode arrangement 829 to the enclosure 803. Tominimize such Rf loss, d4 should be selected as large as possible,minimizing the capacitance between the addressed surfaces, defining theinterspace 832. On the other hand, plasma generation in the addressedinterspace 832 is to be excluded, which requires d4 to be smaller thandark space distance at the prevailing etching conditions.

To resolve this problem, one or more than one electrically floatingmetal screens 830 are provided in the interspace 832, all along thesurface 831 o and the inner surface of the metal enclosure 803. By suchfloating screens, the capacitance between the addressed surfaces is keptsmall but no plasma may ignite in the interspace 832, due to thespacings d5 between neighboring surfaces of the screens or screens andthe surface 831 _(o) as well as the inner surface of the metal enclosure803, respectively, being kept smaller than the dark space distance. Thescreens 830 may be mounted by means of electrically isolating distanceholders 834 as schematically shown in FIG. 8 .

The aspect explained by FIG. 8 is to minimize Rf power loss through aninterspace from a large Rf operated electrode to the surrounding metalenclosure of a vacuum process recipient and thereby avoiding Rf plasmageneration in such interspace by providing one or more than one metalscreens along and in the interspace and mounted in an electricallyfloating manner. All sub interspaces between such screens and betweensuch screens, the electrode surface and the metal enclosure surface, arenarrower than dark space distance at the processing parameters of theprocess to be operated in the vacuum enclosure. This aspect isconsidered possibly inventive per se.

In FIG. 9 there is shown, most simplified and schematically, themeasures according to the invention, to enlarge the effective surface ofthe first electrode arrangement of the capacitive coupled RF vacuumetching apparatus according to the invention, which obeys the law ofKoenig.

The Rf plasma reaction space PL is confined between the larger firstelectrode arrangement 929 and the second, smaller electrode arrangement945 in the vacuum enclosure 903. The electrode arrangements 929, 945 arefed with respect to one another by an Rf supply of one or more than onefrequency. The surface of the first, larger electrode arrangement 829 issignificantly enlarged, by providing at the electrode arrangement 929,at least one metal body 950, e.g. plate shaped or jar-shaped andimmersed in the plasma reaction space PL and operated on the electricpotential of the remainder of the electrode arrangement 929. FIG. 10shows, simplified and schematically the capacitive coupled RF vacuumetching apparatus which, similar to the embodiment of FIG. 1 , comprisesa pumping compartment 1005 with a large pumping port 1013 and an etchingcompartment 1007. Similar to the embodiment of FIG. 1 the second,smaller electrode arrangement 1045, comprising the workpiece carrier1019 c is operated on ground potential and electrically contacts theshroud 1009 with the pumping trough bores and/or trough slits (not shownin FIG. 10 ) once lifted in etching position by distributed resilientcontact members 1056. As the shroud 1009 is electrically connected tothe metal enclosure 1003, similarly to shroud 9 in FIG. 1 to enclosure3, and the enclosure 1003 is operated on electric ground potential, theworkpiece carrier 1019 c as well becomes tightly connected to groundpotential.

In opposition to the grounding concept as addressed in context with FIG.1 according to which the Rf current return path is led via a pair ofparallel impedances, namely via the enclosure 3 along the pumpingcompartment 5 and via the workpiece support 19 down to system ground G,according to the embodiment of FIG. 10 the Rf return path is selected tobe as short as possible. The system ground tab 1023 to system ground Gis provided centrally at the top of the etching compartment 1007. Thegrounding concept shown in FIG. 1 may be replaced by the groundingconcept of FIG. 10 as in both cases the workpiece carrier, as thesecond, smaller electrode arrangement, is operated on ground potentialand not on a biasing potential. FIG. 11 shows, simplified andschematically an embodiment of the apparatus which, similar to theembodiment of FIG. 1 comprises a pumping compartment 1105 with a largepumping port 1113 and an etching compartment 1107. A handling opening1155 is confined by the rim or shroud 1109 with the trough-boresor-slits 1111. The handling opening 1155 is bordered by a frame 1157, ina good variant made of a ceramic material.

In opposition to the interaction of the workpiece carrier 19 c and theworkpiece or substrate 47 with the shroud or rim 9 as shown in FIG. 1 ,according to the form of realization according to FIG. 11 the shroud1109 with the frame 1157 acts as a stop for the workpiece or substrate1147 so that in the etching position of the workpiece carrier 1119 c theupper surface of the workpiece or substrate 1147 is positionedsubstantially flush with the rim or shroud 1109. Thereby the workpieceor substrate 1147 in its etching position becomes firmly biased and heldbetween the workpiece carrier 1119 c and the frame 1157. Additionally,FIG. 11 shows, that the resilient contact members 1156 may bemechanically coupled to the workpiece carrier 1119 c whereas accordingto FIG. 1 they are mechanically coupled to the shroud 9. Both variantsare possible and also a combination in which some of the resilientcontact members 56,1156 are mechanically coupled to the movableworkpiece carrier 19 c, 1119 c, some to the stationary rim or shroud 9,1109. Especially if, as addressed, the border of the shroud or rimmechanically interacts with the workpiece or substrate during theetching operation, it is important to maintain such interactionaccurately constant during the processing. In the embodiment of FIG. 11such interaction is biasing and holding the workpiece or wafer 1147during etch processing. Thus, generically and especially in this case,high mechanical stability must be achieved also in spite of mutualthermal expansions of different materials and structures which couldresult in mutual shift and/or warpage of the frame and shroud with therespective effect on the substrate or workpiece, especially on a thinand large substrate.

In spite of the fact, that in the embodiment according to FIG. 3according to FIG. 3 , different thermal expansions of the spokes 12 andof the frame 57 are well considered by the fact that the ends of thespokes 12 are not firmly linked to the frame 57, this FIG. 3 embodimentis not optimal in the case, as of FIG. 11 , in which the framemechanically interacts with the workpiece or wafer 1147, as during etchprocessing.

FIG. 12 shows most schematically and simplified and in a top view on therim or shroud arrangement 1209, the ring-shaped frame 1257 for acircular workpiece or substrate 1247 in an alternative construction tothat shown in FIG. 3 . It is tailored to exploit the frame 1257 as amechanical stop and down-holding member for the substrate 1247 duringetch processing. Nevertheless, it may also be applied if the substratecattier is stationary as addressed above and no stop is in fact needed.

Only a few of the spokes 1212 are shown in FIG. 12 . The one ends 1212_(e1) of the spokes 1212 are mechanically fixed to the frame 1257, ase.g. by gluing, welding, soldering, screwing. The other ends 1212 _(e2)are mechanically fixed relative to the enclosure 1203, as represented inFIG. 12 only schematically. All the spokes 1212 together form the rim orshroud 1209 with the through-slits 1211 which are narrow enough toprevent plasma burning therein. The spokes 1212 act as leaf springs withrespect to relative expansion E of the frame 1257 with respect to theenclosure 1203. The spokes 1212 which might be curved or bent asschematically shown in dash line at 1212′ define for a length directionD and are mounted to the frame 1257 so, that the directions D of lengthextensions intersect the tangent T on the frame 1257 at the locus ofspoke fixation with an angle α which is not 90°, but smaller than 90°down to 0°. Because in the addressed angle range the angle α is notcritical with respect to the general leaf-spring effect of the spokes1212, the spokes 1212 may be arranged mutually parallel over selectedsections of the circumference of the frame 1257, as schematicallyrepresented in FIG. 12 at 1212 p in dash lines. In fact the spokes actas bendable members.

The frame 1257 becomes stably mounted by the multitude of spokes 1212and may freely expand and retract upon thermal loading without anywarpage, so that a highly accurate positioning and holding of theworkpiece or substrate 1247 is achieved.

As shown in FIG. 12 in at 1212″ the spokes or some of the spokes, mostgenerically being compressible or bendable, may also be arranged underα=90° if compressible as by “zig-zag”- or wave-shaped. They in fact thenact as compressible members.

FIG. 13 shows in a representation in analogy to that of FIG. 3 the rimor shroud 1309 and frame 1357 arrangement for large rectangularsubstrates or workpieces and constructed in agreement with the genericapproach as was just addressed in context with FIG. 12 .

FIG. 14 shows in a partial cross-sectional representation along line B-Bof FIG. 13 the interaction of the liftable and retractable workpiececarrier 1419 c with the substrate or workpiece 1447 with the rim orshroud 1309 and frame 1357 arrangement as of FIG. 13 .

According to FIG. 13 and FIG. 14 , in analogy to the teaching of genericFIG. 12 , the frame 1357 defines the square-shaped handling opening 1355for a square substrate or workpiece.

As may be seen from FIG. 14 and in analogy to FIG. 12 the one ends 1312_(e1) of the spokes 1312 are fixed to the frame 1357. In the specificexample, hey are glued at 1358 and biased between the frame 1357 and aframe counterpart 1357 _(a) in a good embodiment both made of ceramicmaterial as of aluminum oxide.

The other ends 1357 _(e2) (see FIG. 13 ) are rigidly connected directlyor indirectly to the enclosure 1303. Four sections I to IV ofrespectively directed spokes 1312 are provided separate by webs 1358which are not fixed to the frame 1357/1357 _(a) as being providedperpendicularly to the frame tangent at the locus of mutualintersection. In a good embodiment the spokes 1312 the webs 1358 and asurrounding frame like part 1359 of the overall shroud or rim 1309 aremade of a unitary metal plate into which the slits between the spokes1312 are machined.

As becomes apparent from FIG. 14 , the workpiece carrier 1419 _(c)bypasses, when moved in edge-processing position 1147 _(u), the borderof the frame counterpart 1357 _(a), so that the workpiece or substrate1447 becomes biased towards the frame 1357.

It has to be pointed out, that instead of making use of asubstrate-holding frame as of frame 1357, the substrate or workpiece maybe held firmly on the workpiece carrier, as of 1419 _(c), differently,e.g. by making use of electro static forces, thus by means of an electrostatic chuck or by a vacuum chuck establishing below the substrate orworkpiece a pressure, which is smaller than the vacuum exploited for theedging process. In such a case, thermal loading of the shroud or rimmight be substantially less critical.

Differently tailored workpiece carriers or chucks may be exchangeablyapplied in the capacitive coupled RF vacuum etching apparatus accordingto the invention.

In one embodiment, the workpiece carrier is cooled. It comprises asystem of channels for a liquid cooling medium as addressed in dashedlines in FIG. 14 at 1448 and in FIG. 1 in dashed lines as well, at 20.

In embodiments as were addressed, the vacuum enclosure is separate in apumping compartment and in an etching compartment and the substrate orworkpiece is firmly biased and held on a workpiece carrier. Cooling ofthe workpiece or substrate is improved by establishing a cushion of heatconducting gas between the cooled workpiece carrier and the bottomsurface of the workpiece or substrate. The heat conducting gas flowsfrom the interspace between the cooled surface of the workpiece carrierand the bottom surface of the workpiece or substrate into the pumpingcompartment and only neglectably into the etching compartment.

This approach at an embodiment of the apparatus, is schematically shownin FIG. 15 . The workpiece carrier 1519 is cooled as by means of asystem of channels 1548 for a liquid cooling medium. The workpiececarrier 1519 _(c) further comprises a gas-channel system 1550 adjacentand along its upper surface 1552. Bores or slits 1554 connect the gaschannel system 1550 to the surface 1552 of the workpiece carrier 1519_(c). The gas channel system 1552 is connected to a gas source for aheat conduction gas (not shown). The gas channel system 1552 and theslits or bores 1554 are tailored so as to establish along the bottomsurface of the workpiece or substrate 1547 a substantially homogeneouspressure distribution at most with an increased pressure along theperiphery of the workpiece carrier 1519 _(c) and thus along theperiphery of a substrate or workpiece 1547. The skilled artisan knowshow to establish a respective pressure distribution along the bottomsurface of the workpiece or substrate by respectively tailoring thedistribution of the flow resistances along the gas channel system 1552and/or the distribution of the bores or slits 1554 and/or thedistribution of the flow resistances of the bores or slits 1554.

As schematically shown qualitatively over the radial extent r of theworkpiece carrier 1519, the pressure p is established to besubstantially constant along the surface of the workpiece carrier orwith a respective maximum, as shown in dashed lines, along the peripheryof the substrate or workpiece 1547.

In those embodiments of the apparatus in which a shroud or rim dividesthe overall vacuum recipient or enclosure in an etching compartment andin a pumping compartment, the heat conducting gas flow may leave theinterspace between the substrate or workpiece and the upper surface ofthe workpiece carrier merely into the pumping compartment as shown inFIG. 15 at HG. Here the etching compartment 1507 is separate from thepumping compartment 1505 by the shroud or rim arrangement 1509. Duringprocessing the workpiece or substrate 1547, the workpiece or substrate1547 is mechanically held e.g. by the frame 1557 and substantially sealsthe etching compartment from the pumping compartment. Thus the twocompartments communicate with respect to gas flow and during processingmerely through the bores or slits in the shroud or rim 1509. Because theinterspace between the upper surface of the cooled workpiece carrier1519 c and the bottom surface of the workpiece or substrate 1547 islocated, during processing, on the pumping compartment-1505-side of theframe 1557, the heat conducting gas HG leaves the addressed interspaceexclusively into the pumping compartment 1505. Thereby, the edgingcompartment and the edging process is not influenced by the heatconducting gas HG as e.g. He.

One or more than one apparatus according to the invention may beexploited in a so called inline workpiece or substrate processing plant,wherein at least one workpiece or at least one batch of workpieces istransported from one processing station to the next in a fixed sequenceof processing stations. Such a plant is schematically shown in FIG. 16 .

A workpiece or substrate or a batch of workpieces or substrates 1647 isconveyed along a processing plant 1600, comprising chain of treatingstations 1601 ₁, 1601 ₂ . . . . At least one of the treating stations isan apparatus according to the invention under at least one of itsaspects. The treating station 1601 ₁ may e.g. be a degasser station, thetreating station 1601 ₂ the addressed apparatus. In the plant 1600according to FIG. 16 one workpiece or substrate or one batch thereof issimultaneously treated in each of the treating stations 1601 _(n) andone workpiece or substrate or one batch thereof is simultaneouslyconveyed from one treatment station to the next one. If we address asingle workpiece or substrate also as a batch (just with one singleworkpiece or substrate) in the embodiment of the inline plant 1600 ofFIG. 16 , the extent of batches conveyed and of batches treated isconstant along the chain. The path of conveyance PC may thereby belinear or curved e.g. circularly bent as exemplified in dash line atPCF′. The apparatus provided and according to the invention may beconstructed with a liftable workpiece carrier or with not-liftableworkpiece carrier. If more than one such apparatus is provided, some maybe constructed with liftable workpiece carrier, some with not-liftableworkpiece carrier. They need not be constructed equally but mayincorporate one or more than one different embodiments.

In the FIG. 17 —embodiment of an inline plant 1700 incorporating atleast one of the apparatus according to the invention and possiblyrealizing at least one embodiment thereof, the number of batches(possibly of just one workpiece or substrate) simultaneously treated inthe treating stations 1701 ₁, 1701 ₂, 1701 ₃ is different. As anexample, a degasser station 1701 ₁ simultaneously treats a number N ofbatches, a cooling station 1701 ₂ simultaneously treats a differentnumber M of batches, whereas the apparatus according to the invention,1701 ₁, treats one batch simultaneously. The average rate of batchesinput to and of batches output from the treatment stations is equal.

Thereby the number of batches simultaneously input to and simultaneouslyoutput from a treatment station considered may be different. The path ofconveyance PC may be linear or curved e.g. circularly bent asexemplified in dash line at PC′. The apparatus provided and according tothe invention may be constructed with a liftable workpiece carrier orwith a not-liftable workpiece carrier. If more than one apparatus isprovided, some may be constructed with liftable workpiece carriers, somewith not-liftable workpiece carriers. They need not be constructedequally.

FIG. 18 shows a specific example of an in-line plant 1800 incorporatingone or more than one apparatus according to the invention.

The workpiece or substrate is a foil 1847 unwound from a coil 1851 andrewound on a coil 1852. Between the coils the foil 1847 is passedthrough a vacuum processing plant 1800 incorporating at least oneapparatus 1801 according to the invention. In this embodiment, theworkpiece carrier of the apparatus 1801 is not-liftable.

According to FIG. 19 least one apparatus according to the invention isintegrated in a non-inline plant 1900 which may be said a cluster-plant.More than one treating stations 1801 ₁, 1801 ₂ etc. are loaded andunloaded with one or more than one batch 1947 (the batch may compriseonly one workpiece or substrate) by a central handler 1950. The handler1950 has at least one drivingly expandable and retractable arm 1952 witha support 1954 for the batch 1947 and is drivingly rotatable about thecentral axis A. In this plant which incorporates at least one of thereactors according to the invention, the sequence of treating stationsto which a batch 1947 is fed, the number of batches 1947 simultaneouslyconveyed, the number of batches simultaneously treated in respectivetreating stations and the treatment durations in the respectivetreatment stations is selectable and variably controllable. Theapparatus provided and according to the invention may be constructedwith a liftable workpiece carrier or with a not-liftable workpiececarrier. If more than one apparatus are provided, some may beconstructed with liftable workpiece carriers, some with not-liftableworkpiece carriers. They need not be constructed equally.

Summarizing a Further Aspect of the Vacuum Apparatus as DescribedConsidered Possibly Inventive Per Se:

-   -   A vacuum apparatus comprising an enclosure (3) and a workpiece        carrier and wherein said enclosure (3) is subdivided in a        pumping compartment (7) comprising a pumping port (13) and a        treating compartment (5) said compartments (5,7) being separate        by a shroud or rim (9) having a pattern of through openings or        through slits (11), baring plasma at predetermined processing        conditions, said workpiece carrier being drivingly movable from        a load-/unload position into a processing position and vice        versa, a workpiece or substrate on said workpiece carrier (19 c)        being mechanically held (57) on said workpiece carrier in said        processing position by a downholding member (57) and all along        the periphery of the workpiece or substrate surface exposed to        said treating compartment, said workpiece carrier (19 c)        comprising a channel arrangement (20) adapted to hold a liquid        heating or cooling medium and a further channel arrangement        adapted to hold a heat conduction gas communicating by a bore-        or slit-arrangement with an interspace between the surface of        said workpiece or substrate opposite said surface being exposed        to said treating compartment.

What is claimed is:
 1. A capacitively coupled RF vacuum etchingapparatus constructed for etch operating under predetermined conditionsand comprising: a vacuum recipient—also addressed as enclosure— in saidvacuum recipient a plasma space in operational contact solely with oneelectrode arrangement consisting of a first electrode arrangement and ofa second electrode arrangement facing said first electrode arrangement;said first electrode arrangement defining a first electrode surfaceexposed to said plasma space; said second electrode arrangement defininga second electrode surface exposed to said plasma space, and comprisingthe surface of a workpiece carrier; the first electrode surface beinglarger than the second electrode surface; said first electrodearrangement being electrically connected to an output arrangement of aRf generator arrangement via a match box arrangement, generating aplasma supply Rf signal; and all components of said first electrodearrangement being at a common electrical RF potential and all componentsof said second electrode arrangement being at a common electricalpotential, wherein said first electrode arrangement comprises a metalbody with opposing upper and lower surfaces and peripheral edges thatare freely exposed to and fully immersed in said plasma space, saidopposing upper and lower surfaces and said peripheral edges being a partof said first electrode surface.
 2. The capacitively coupled RF vacuumetching apparatus according to claim wherein said metal body comprises apattern of through openings and/or through slits tailored so that, inoperation, plasma burns in said through openings at said predeterminedconditions.
 3. The capacitively coupled RF vacuum etching apparatusaccording to claim 1, wherein said first electrode surface comprises afirst surface area extending along a first plane, a second surface areaextending along a second plane, said first and second surface areasdefining an interspace tailored so that, in operation, plasma is burningin and along said interspace at said predetermined conditions.
 4. Thecapacitively coupled RF vacuum etching apparatus according to claim 3,wherein said second electrode surface comprises a surface area extendingalong a third plane and said first, second and third planes are parallelplanes.
 5. The capacitively coupled RF vacuum etching apparatusaccording to claim 1, wherein said metal body is a plate.
 6. Thecapacitively coupled RF vacuum etching apparatus according to claim 1,wherein: said Rf generator arrangement generates at least one firstplasmas supply signal at a very high frequency at said outputarrangement and at least one second plasma supply signal at a highfrequency lower than said very high frequency at said outputarrangement, said first electrode arrangement is electrically connectedvia said match box arrangement to said output arrangement and iselectrically supplied, in operation, by said first and by said secondplasma supply signals; said second electrode arrangement is, at leastduring etching operation, electrically connected to a system ground tab.7. The capacitively coupled RF vacuum etching apparatus according toclaim 6, wherein said first plasma supply signal and said second plasmasupply signal are connected to said first electrode arrangement atlocally different contact points.
 8. The capacitively coupled RF vacuumetching apparatus according to claim 1, wherein said Rf generatorarrangement is connected to said first electrode arrangement at morethan one locally different contacting points.
 9. The capacitivelycoupled RF vacuum etching apparatus according to claim 6, wherein thereis valid:10 MHz≤f_(vhf)≤400 MHzor10 MHz≤f_(vhf)≤300 MHzor20 MHz≤f_(vhf)≤300 MHzor20 MHz≤f_(vhf)≤100 MHzand:0.01 f_(vhf)≤f_(hf)≤0.5 f_(vhf)or0.05 f_(vhf)≤f_(hf)≤0.5 f_(vhf) f_(hf) being the frequency of the highfrequency supply signal and f_(vhf) the frequency of the very highfrequency supply signal.
 10. The capacitively coupled RF vacuum etchingapparatus according to claim 1, wherein said workpiece carrier isdrivingly movable towards and from said first electrode arrangement. 11.The capacitively coupled RF vacuum etching apparatus according to claim1, wherein said workpiece carrier is not movable towards and from saidfirst electrode arrangement.
 12. The capacitively coupled RF vacuumetching apparatus according to claim 1, wherein said workpiece carrieris not movable towards and from said first electrode arrangement andsaid first electrode arrangement comprises a drivingly movable door forloading/unloading a workpiece.
 13. The capacitively coupled RF vacuumetching apparatus according to claim 1, wherein said enclosure issubdivided into a pumping compartment comprising a pumping port and inan etching compartment comprising said first electrode arrangement, saidcompartments being separated by a shroud or rim having a pattern ofthrough openings or through slits, tailored so, that, in operation,plasma does not burn therein at said predetermined etching conditions.14. The capacitively coupled RF vacuum etching apparatus according toclaim 1, wherein said enclosure is subdivided into a pumping compartmentcomprising a pumping port and in an etching compartment comprising saidfirst electrode arrangement, said compartments being separated by ashroud or rim, said shroud or rim holding a frame defining a workpieceaccess opening to said etching compartment, said frame being held bysaid shroud or rim by means of a multitude of spokes mutually definingthrough-gaps between said pumping and said etching compartments, saidthough-gaps being tailored so that, in operation, plasma does not burntherein at said predetermined etching conditions, said frame being heldby said rim or shroud by means of said spokes.
 15. The capacitivelycoupled RF vacuum etching apparatus according to claim 1, wherein saidenclosure is subdivided into a pumping compartment comprising a pumpingport and an etching compartment comprising said first electrodearrangement, said compartments being separated by a shroud or rim,having a pattern of through openings or through slits tailored so, that,in operation, plasma does not burn therein at said predetermined etchingconditions, said shroud or rim holding a frame defining a workpieceaccess opening to said etching compartment, said frame being mounted tosaid shroud or rim, said workpiece carrier being drivingly movable froma load-/unload position into a processing position and vice versa, saidframe acting as a downholding member for a workpiece or substrate onsaid workpiece carrier in said processing position.
 16. The capacitivelycoupled RF vacuum etching apparatus according to claim 1, wherein saidenclosure is subdivided into a pumping compartment comprising a pumpingport and an etching compartment comprising said first electrodearrangement, said compartments being separated by a shroud or rim, saidshroud or rim holding a frame defining a workpiece access opening tosaid etching compartment, said workpiece carrier being drivingly movablefrom a load-/unload position into a processing position and vice versa,said frame acting as a downholding member for a workpiece or substrateon said workpiece carrier in said processing position and said shroud orrim being linked to said frame by means of a multitude of spokesmutually defining through-gaps between said pumping and said etchingcompartments, said through-gaps being tailored so, that, in operationplasma does not burn therein at said predetermined etching conditions,said frame being mounted to said shroud or rim by means of said spokesin such a manner, that said frame may freely expand and retract underthermal loading.
 17. The capacitively coupled RF vacuum etchingapparatus according to claim 14, wherein said spokes are constructed ascompressible and/or bendable members.
 18. The capacitively coupled RFvacuum etching apparatus at least according to claim 14, wherein saidspokes define a direction of length extent each and are mounted to saidframe so, that the respective direction of length extent intersect thetangent on said frame at the locus of respective spoke fixation with anangle α for which there is valid:90°>α≥0°.
 19. The capacitively coupled RF vacuum etching apparatusaccording to claim 1, wherein said workpiece carrier comprises a channelarrangement adapted to receive a liquid heating or cooling medium. 20.The capacitively coupled RF vacuum etching apparatus according to claim1, wherein said enclosure is subdivided into a pumping compartmentcomprising a pumping port and in an etching compartment comprising saidfirst electrode arrangement, said compartments being separated by ashroud or rim having a pattern of through openings or through slits,tailored so, that, in operation, plasma does not burn therein at saidpredetermined etching conditions, said workpiece carrier being drivinglymovable from a load-/unload position into a processing position and viceversa, a downholding member constructed to hold a workpiece or substratedown on said workpiece carrier in said processing position at and alongthe periphery of the workpiece or substrate surface exposed to saidetching compartment, said workpiece carrier comprising a channelarrangement adapted to receive a liquid heating or cooling medium and afurther channel arrangement adapted to receive a heat conduction gas anddischarging by a bore- and/or slit-pattern at the carrier-surface ofsaid workpiece carrier for said workpiece or substrate.
 21. Thecapacitively coupled RF vacuum etching apparatus according to claim 20,said further channel arrangement and pattern of bores and/or slitsdischarging at said carrier-surface being tailored so as to establishalong the periphery of an interspace between said carrier-surface and asubstrate or workpiece a pressure of heat conducting gas which is atleast equal to the pressure in the and along the more central parts ofsaid interspace.
 22. The capacitively coupled RF vacuum etchingapparatus according to claim 1, wherein said enclosure is subdividedinto a pumping compartment comprising a pumping port and in an etchingcompartment comprising said first electrode arrangement, saidcompartments being separated by a shroud or rim having a pattern ofthrough openings or through slits being tailored so that, in operation,plasma does not burn therein at said predetermined etching conditions,said shroud or rim being a part of said enclosure or comprising a partof said enclosure and a part of said first electrode arrangement. 23.The capacitively coupled RF vacuum etching apparatus according to claim1, wherein said enclosure is subdivided into a pumping compartmentcomprising a pumping port and an etching compartment comprising saidfirst electrode arrangement, said compartments being separated by ashroud or rim having a pattern of through openings and/or through slits,being tailored so that, in operation, plasma does not burn therein atsaid predetermined etching conditions, said workpiece carrier beingdrivingly movable from a load-/unload position into a processingposition and vice versa, said shroud or rim being electrically connectedto said workpiece support in said processing position by distinct,distributed and resilient contact members.
 24. The capacitively coupledRF vacuum etching apparatus according to at least claim 1, wherein saidRf generator arrangement generates at least one first plasmas supplysignal at a very high frequency at an output arrangement and at leastone second plasma supply signal at a high frequency, lower than saidvery high frequency, at said output arrangement, said first electrodearrangement is electrically connected via a match box arrangement tosaid output arrangement and is electrically supplied, in operation, bysaid first and by said second plasma supply signals; said secondelectrode arrangement is electrically connected to a system ground tabsaid generator arrangement generating said first plasma supply signal at60 MHz, said second plasma supply signal at about 13 MHz.
 25. Thecapacitively coupled RF vacuum etching apparatus according to claim 1,the predetermined, pressure condition for said etching being 0.1 to 0.5Pa both limits included.
 26. The capacitively coupled RF vacuum etchingapparatus according to claim 1, wherein a spacing between a first partof said surrounding surface of said metal body freely exposed to andimmersed in said plasma space (PL) and a second part of said firstelectrode surface, facing said first part is 10 mm to 40 mm.
 27. Thecapacitively coupled RF vacuum etching apparatus according to claim 1,wherein a spacing between a predominant part of said first electrodesurface and facing said workpiece carrier and a predominant part of thesurface of said workpiece carrier is 40 mm to 80 mm.
 28. Thecapacitively coupled apparatus of claim 1, being shaped for rectangularor square substrates.
 29. The capacitively coupled RF vacuum etchingapparatus of claim wherein said Rf generator arrangement is constructedto at least one of frequency modulating and of power modulating at leastone Rf supply signal to said first electrode arrangement duringoperation.
 30. The capacitively coupled RF vacuum etching apparatus ofclaim 1, wherein at least one of the following features prevails: the Rfgenerator arrangement is tailored to supply a very high frequency supplysignal and high frequency supply signal to said first electrodearrangement, the frequency of said very high frequency supply signalbeing an integer multiple of the frequency of said high frequency supplysignal; the Rf generator arrangement is tailored to supply a very highfrequency supply signal and high frequency supply signal to said firstelectrode arrangement and to phase lock said supply signals; the Rfgenerator arrangement is tailored to supply a very high frequency supplysignal and high frequency supply signal to said first electrodearrangement and for adjusting mutual phasing of said supply signals; theRf generator arrangement is tailored to supply a very high frequencysupply signal and high frequency supply signal to said first electrodearrangement and to vary mutual phasing of said supply signals duringoperation.
 31. A workpiece or substrate processing plant comprising atleast one capacitively coupled Rf apparatus according to claim and beinga plant wherein the stations may be loaded and unloaded with at leastone workpiece or substrate at a selectable rhythm by a handler, as by acentral handler.
 32. A method of etching or of manufacturing etchedworkpieces or substrates by making use of the capacitively coupled RFvacuum etching apparatus according to claim
 1. 33. The method of claim32, said etching being performed in a reactive gas atmosphere.
 34. Themethod of claim 33, said reactive gas atmosphere containing oxygen oroxygen and fluorine.